A Novel Cerium(IV)-Based Metal-Organic Framework for CO2 Chemical Fixation and Photocatalytic Overall Water Splitting.

Abstract

Cerium (IV)-based metal-organic frameworks (MOFs) are highly desirable due to their unique potential in fields such as redox catalysis and photocatalysis. However, due to the high reduction potential of CeIV species in solution, it is still a great challenge to synthesize CeIV -MOFs with novel structures, which are extremely dominated by the hexanuclear Ce-O cluster inorganic building units (IBUs). Herein, a Ce-O IBU chain containing CeIV -MOF, CSUST-3 (CSUST: Changsha University of Science and Technology), was successfully prepared using the kinetic stabilization study of UiO-66(Ce)-NDC (H2 NDC=2,6-naphthalenedicarboxylic acid). Furthermore, owing to the superior redox activity, Lewis acidity and semiconductor-like behavior owing to Ce4+ , activated CSUST-3 was demonstrated to be an excellent catalyst for CO2 chemical fixation. One-pot synthesis of styrene carbonate from styrene and CO2 was achieved under mild conditions (1 atm CO2 , 80 °C, and solvent free). Moreover, activated CSUST-3 was shown to be a remarkable co-catalyst-free photocatalyst for overall water splitting (OWS), rendering 59 μmol g-1 h-1 of H2 and 22 μmol g-1 h-1 of O2 under simulated sunlight irradiation (Na2 S-Na2 SO3 as sacrificial agent).